The compound N-[1-(2-ethoxyethyl)-5-(N-ethyl-N-methylamino)-7-(4-methylpyridin-2-yl-amino)-1H-pyrazolo[4,3-d]pyrimidine-3-carbonyl]methanesulfonamide has the following structure (1):
The synthesis of N-[1-(2-ethoxyethyl)-5-(N-ethyl-N-methylamino)-7-(4-methylpyridin-2-yl-amino)-1H-pyrazolo[4,3-d]pyrimidine-3-carbonyl]methanesulfonamide is described in Example 115 of published PCT application WO 2005/049616 (the “Compound Application”). The Compound Application further discloses that N-[1-(2-ethoxyethyl)-5-(N-ethyl-N-methylamino)-7-(4-methylpyridin-2-yl-amino)-1H-pyrazolo[4,3-d]pyrimidine-3-carbonyl]methanesulfonamide is a phosphodiesterase-5 (“PDE-5”) inhibitor that can be used to treat a PDE-5-mediated condition, such as hypertension.
Different solid-state forms of a pharmaceutical compound can have materially different physical properties. Such differences in physical properties can have an impact, for example, on how a pharmaceutical compound is made, processed, formulated or administered. Accordingly, the identification of new solid-state forms of N-[1-(2-ethoxyethyl)-5-(N-ethyl-N-methylamino)-7-(4-methylpyridin-2-yl-amino)-1H-pyrazolo[4,3-d]pyrimidine-3-carbonyl]methanesulfonamide that provide an advantage relative to other solid-state forms in making, processing, formulating or administering the compound are desirable. As discussed below, three new anhydrous crystalline forms of N-[1-(2-ethoxyethyl)-5-(N-ethyl-N-methylamino)-7-(4-methylpyridin-2-yl-amino)-1H-pyrazolo[4,3-d]pyrimidine-3-carbonyl]methanesulfonamide have been identified.